The present invention relates to the field of water-rich liquid wastes of various origins, such as industrial, farm and city wastes. It relates more particularly to a process making it possible to transform strong acidic wastes, having a pH of less than 2, into solid materials having great stability with respect to external agents, such as water. These liquid wastes possess a great retention power for polluting elements which are contained in these liquid wastes.
The increasing volume of wastes and residues, of all types, constitutes a problem which is of great concern to manufacturers and municipalities, particularly when one considers the fact that these wastes generally present great danger for the environment and for living beings. This is particularly a problem when these liquid wastes are strongly acidic.
Most often, the only acceptable solution from the economic and ecological viewpoint is to perform a treatment of these wastes, by physical or chemical means to effect solidification thereof. For this purpose, techniques have already been proposed which consist in mixing the waste slurry with suitable proportions of various ingredients, such as Portland cement, sodium silicate containing a setting agent such as lime, gypsum, calcium carbonate, a mixture of lime and pozzolana, gypsum or plaster in admixture with organic resins, or metallurgical slags carried in an alkaline medium in the presence of agents catalyzing the hydration of the slag.
These various processes rather often have offered interesting solutions to the solidification of muddy wastes but they resort to using treating products, as for example, Portland cement or similar products, the production of which involves high energy consumption. Further, they are not suitable in the particular case of treating liquid muds that are rich in water and very strongly acidic.